HD 427 Rear End
Thread Starter
Racer
Joined: Sep 2004
Posts: 381
Likes: 2
HD 427 Rear End
I've been looking around for weeks trying to figure out what the difference is between the "H.D. "427 3.08 gear rear end , and a non H.D. 427 3.08 gear rear end in my 69.
What motor would it need to have the "H.D"?
I don't see an option for H.D. rear end in the Black Book, or anywhere else for that matter.
The code on the rear end reads "1AT2 69W" can't read anything else on it.
Thank in advance for any clues!
What motor would it need to have the "H.D"?
I don't see an option for H.D. rear end in the Black Book, or anywhere else for that matter.
The code on the rear end reads "1AT2 69W" can't read anything else on it.
Thank in advance for any clues!
Thread Starter
Racer
Joined: Sep 2004
Posts: 381
Likes: 2
Yes, it has the caps on the side yokes.
I'm wondering how you got an HD vs. a standard rear end. Did you need a certain motor? Or suspension option?
My tank sticker shows GS2 for 3.08 posi. The area on the tank sticker for the engine option is long gone, the original motor is also long gone.
I'm wondering how you got an HD vs. a standard rear end. Did you need a certain motor? Or suspension option?
My tank sticker shows GS2 for 3.08 posi. The area on the tank sticker for the engine option is long gone, the original motor is also long gone.
Team Owner
Joined: Sep 2006
Posts: 31,270
Likes: 4,362
From: Westminster Maryland
Hi GS,
My understanding is that in 69 there were standard and optional trans/differential combinations for various engines.
For example:
The 350/350 with the 2.52:1, 4-speed, had the 3.36 as the std differential and the 3.55 as the optional performance differential.
The same engine with the 2.20:1, 4-speed, had the 3.70 as the std differential and the 4.11 as the optional performance differential.
The 427/435 with the 2.20:1, 4-speed, had 3.55 as the standard differential, the 3.36 as economy, the 3.70 as performance, and the 4.11 as special high performance.
I believe small blocks used the U shaped clamps while big blocks used the block type caps. I also believe that the LT-! (70-72) was the only sb engine that included the HD/bb style caps as part of it's option.
Hope this helps.
Regards,
Alan
My understanding is that in 69 there were standard and optional trans/differential combinations for various engines.
For example:
The 350/350 with the 2.52:1, 4-speed, had the 3.36 as the std differential and the 3.55 as the optional performance differential.
The same engine with the 2.20:1, 4-speed, had the 3.70 as the std differential and the 4.11 as the optional performance differential.
The 427/435 with the 2.20:1, 4-speed, had 3.55 as the standard differential, the 3.36 as economy, the 3.70 as performance, and the 4.11 as special high performance.
I believe small blocks used the U shaped clamps while big blocks used the block type caps. I also believe that the LT-! (70-72) was the only sb engine that included the HD/bb style caps as part of it's option.
Hope this helps.
Regards,
Alan
Team Owner
Joined: Sep 2006
Posts: 31,270
Likes: 4,362
From: Westminster Maryland
Hi GS,
AT is the 3.08 BB HD Posi. Here's a list of the 3.08 applications, so could the AT appear on ANY of these? There were also codes AV and AW that were BB HD 3.08 ratio differentials.
It was std for 427/390 w/2.52:1
It was the econ. option for the 427/390 w/2.20:1
It was std for 427/390 Turbo Hydra-Matic
The same usage for 427/400
It was std for 427/435 Turbo Hydra-Matic
It was std for 427/430 Turbo Hydra-Matic
That's all!
Regards,
Alan
AT is the 3.08 BB HD Posi. Here's a list of the 3.08 applications, so could the AT appear on ANY of these? There were also codes AV and AW that were BB HD 3.08 ratio differentials.
It was std for 427/390 w/2.52:1
It was the econ. option for the 427/390 w/2.20:1
It was std for 427/390 Turbo Hydra-Matic
The same usage for 427/400
It was std for 427/435 Turbo Hydra-Matic
It was std for 427/430 Turbo Hydra-Matic
That's all!
Regards,
Alan
Last edited by Alan 71; Apr 18, 2010 at 04:18 PM.
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St. Jude Donor '08-'09-'10-'11-'12
....the "original owner" on my lowly '74 L-48 automatic coupe with no A/C ordered a "heavy duty battery" and a "heavy duty 3.08:1 rearend". It also has the caps instead of the straps.
